Improvement in vakiable cut-off valve-geak



@gettati tatrrs gtttat @ffice J. L. niciciNso-N, or `D-jUBUQUE, Iowa.

LettersPatent No. 68,492,1iatefl September 3, 1867.. i

IMPROVEMENT 4Ill VARIABLE GUT-OFF VALVE-GEAR.

'ro ALLwHoM-Ir MAY eoNcEnN;

Be it known that I, J. I1. DICKINSON,-of Dubuque, in the county of Dubuque, and State of Iowa, have invented a new and useful Improvement imVariable Cut-`Ofi` and I do hereby declare that the following is a full, lclear, and exact description thereof, which will enable those skilled in the art to makev and use the same, reference being had to the accompanying drawings, forming part of lthis specification. i

This invention relates to tho manner in which the steam is admitted to the steam-chest of' a steam engine, whereby the quantity used is made variable, so as toi conform to the power required of the enginegand it consists in attaching -to the rod or stein of the oscillating valve an arln, which is operated by two eccentric-rods 'having different motions, Awhich are connected with the arm by means of a slide, the position, of which slide on the arm is controlled by the governor, thereby cutting oft the steam at an earlier or later point, also decreasing or increasing the throwof the cut-of valve. i i l It also consistsin an automatic device for detaching the govcrnor,and. thereby closing the valve and stopping the engine in case ei' accident, as will be hcrcinaftermore fully described.

Figure I is a side view of the arm with the slide attached. y

Figure 2 is an edgeV view of the same. I

FigureB is a'revcrse side view of tig. I.

'Figure 4 is a cross-section,throughofniet tig. 3. K

Figure 5 is a side view of the sliding plate, to which the wristof the governor-'rod is att-ached, and whichwrst is made detachable for certain pur/poses. A i i Figure G shows a top view of the wrist detached from theplate.

The position of 'the cut-oifva'lve, in connection with the steam-chest 'and main valve of the engine, is shown Tin red lines in the drawing. i

Similar letters ofreferenee indicate corresponding parts. l

vrepresent-s the stem ofthe oscillating cut-od' valve. -B is the arm which is attached to this stem. C represents a sliding block on the arm'B., made intwo parts. D is a bar, which is vibrated on its centrehy the eccentric-rodsE and F., This bar-D is supported and held in its place by the arm G, which is attached to the valve stem, andthrongh which the `pivot passes Anponwhich the barzvibrates. The edges of the bar D are bevelled, and th'e block G is attached to it by cleats an, which fit the bevelled edges,'so that thc connection is in the form of a dove-tail, which allows the block a free sliding movement on the bar, while, at the same time, it slides on the arm 13. The governor is connected with. the block C by the sliding-plate II,`a detailed view of whicliis seen in tig. 5. This plate is adjustablev in the block through the slot ct, and is fastened in place by the screw and nntb. This sliding-plate is vinadcrin' two pieces, the wrist-`pin to which the governor-rod is attached being` on the upper part, but thcvtwo parts are held together-by a hook, c, and pin, d.' Fig. 6 is a top view of thissliding-plate, showing the way in which the two parts are connected together. e is the wrist-pin, to which the governor-rod is attached. When the'engine is running, and the cut-oil` valve in operation, the two parts of the plate H would appear as seenin fig. 3. f is a spring, which is attached to the wrist-pin c, and which bears against hook c to keep it inplace. g is a button, which is attached to the edge of the arm B.

' This arrangement -is made vfor the purpose of detaching the governor-rod or severing the connection between the governor and the slideC, and closing the valve in case thc governor-belt of the engine should break. In such a case, 'the slide C 'would be Adrawn up by the governor so far on the arm B that the inclined projecting end of the hook wouldstrike the button y, and the hook would be forced from the pin d, when the two parts of the plate H would be instantlylseparated, and thc slide would drop down till it struck the stop-pin z.,'which would entirely shut off the steam and stop the engine.

i As before stated, the barD is oscillatcd by the cccentric-rods E and F, and in this connection-it should be stated that the slide 1G is formed oi two parts, which, as seen in iig. 4, may be marked 1 and 2. z' is a disk, which is surrounded hy the part 52.,` although it is attached tothe part 1 by the screws' o o. The bevelled or dove-tailed connection between z' and the part 2 allows the latter a rotating motion, se that the part Z (which Shows as C in iig. 1) can adjustitseli` to vsuit the action ofthe eccentric-rods. I

The rod F may receive its motion directly'from an eccentric, or in any other suitable manner, but it is' set i partake of the earlier (or advance) motion and diminished throw, ther substantially as shown and described, I claim the ec or placed in such a position that its motion will be somewhat (say one-eighth) in advance of the other rod, so that, as the governor moves the sliding-block C from the upper rod towards the lower one, the-arm B' will eby closing the valve :1t an earlier point of the stroke; and as the sliding-block is raised towards the upper rod, the arm B receives a later motion and increased throw, thereby admitting steam to the cylinder for a longer portion of the stroke.

It will thus be seen that the increased or diminished throw of the valve, produced by tho actionof the governor, is combined with the variable action ofthe eccentrics, whereby the valve is rendered much more sensitive to variations of speed, and the engine given a uniform motion.

I do not confine myself` to this particular arrangement as regards the actions of the eceentrics or their cfl'ect upon the oscillating vulve, as I auraware that this motion and eect may be produced byA other means than ernployinfar the bar D. Y

l3nt having thus described my invention, I claim as new, and desire to secure by Letters Patent- 1. In combination with the sliding-block C, formed of the parts 1 and, and actuated by the `governor, centric-rods E and F, acting upon the bar D or its equivalent and upon the oscillating valve, thereby imparting to the arm the motion of either eccentric-rod, as the speed of the engine requires, substantially as shown and described.

2. The arm G and bar D, in combination with vthe valve-stem A, to support and maintain eccentric-rods E and F at a uniform distance from the valve-stem or its equivalent, substantially as described.

I claim the two eccentric-rods, E and F, arranged with reference to the governor and arm G, for the purposes herein sot forth.

J, L. DICKINSON.

Witnesses:

WM. F. McNAMAim,A ALEX. F, teneurs.

Xen/ 

